Volvo does NOT require that any newer cars ATF ever gets flushed UNLESS it's an AWD with issues or used for towing.

Most dealers recommend periodic ATF flushes and it's then up to the techs to check the fluids condition (color) and advise a flush. It usually looks OK until about 60K miles.

Did you ever have you fluid flushed? If not, I'm not surprized that it failed at your mileage. I've seen a few trannies go to 150K miles on original ATF so some can go farther with neglect but most don't.

BTW, you won't get anywhere trying to complain to VCNA about that or anything else with an older car and yes, a '98 is older (way past warranty).